Sheet feeder assembly

ABSTRACT

An improved sheet feeder assembly includes a feed foot having a friction or feed wheel which is disposed in pressure engagement with a sheet to be fed. An electrical vibrator assembly moves the feed foot through forward and return strokes. During a return stroke, the friction wheel rolls along an upper surface of a sheet. During a forward or feed stroke, a one-way clutch assembly holds the friction wheel against rotation so that the sheet is moved forwardly with the friction wheel. As the friction wheel moves forwardly, it also moves toward a guide or register surface to square-up or side register a skewed sheet as it is fed forwardly. The vibrator assembly and feed foot are mounted on a four bar linkage arrangement so that the orientation of the feed foot relative to a pile of sheets is maintained constant as sheets are fed from the pile. The pressure with which the friction wheel engages a sheet is controlled by a counter-weight which is adjustable to vary the pressure between the friction wheel and a sheet.

United States Patent 1 Kolibas 1 July 10, 1973 SHEET FEEDER ASSEMBLY James A. Kolibas, Broadview Heights, Ohio [75] Inventor:

[73] Assignee: Addressograph-Multigraph Corporation, Cleveland, Ohio [22] Filed: May 13, 1971 [21] Appl. No.: 143,025

Primary Examiner-Richard E. Aegerter Assistant Examiner-Bruce H. Stoner, Jr. Attorney-Russell L. Root and Ray S. Pyle [57] ABSTRACT An improved sheet feeder assembly includes a feed foot having a friction or feed wheel which is disposed in pressure engagement with a sheet to be fed. An electrical vibrator assembly moves the feed foot through forward and return strokes. During a return stroke, the friction wheel rolls along an upper surface of a sheet. During a forward or feed stroke, a one-way clutch assembly holds the friction wheel against rotation so that the sheet is moved forwardly with the friction wheel. As the friction wheel moves forwardly, it also moves toward a guide or register surface to square-up or side register a skewed sheet as it is fed forwardly. The vibrator assembly and feed foot are mounted on a four bar linkage arrangement so that the orientation of the feed foot relative to a pile of sheets is maintained constant as sheets are fed from the pile. The pressure with which the friction wheel engages a sheet is controlled by a counter-weight which is adjustable to vary the pressure between the friction wheel and a sheet.

4 Claims, 7 Drawing Figures SHEET FEEDERASSEMBLY This invention relates generally to anassembly for feeding sheets of material and more particularly to an improved sheet feeder assembly in which a feed foot is moved through feed and return strokes by a vibrator.

Sheets to be copied, i.e. originals, are commonly fed in sequence from a pile to a copier. Under certain circumstances a pile of originals may include sheets of different sizes and weights. In addition, some of these sheets may be dog-cared", torn or punched. Even though the originals may have different physical characteristics, each original should be quickly fed in turn into the copier as soon as it is ready to receive it in order to promote efficient use of the copier. Also, the manner in which the sheets are fed should remain constant even though the height of the pile decreases as the sheets are fed.

There are many known types of sheet feeders, including vacuum feeders, friction rolls with either corner snubbers or retard action rolls, and stickey foot feeders. While these known types of sheet feeders have been more or less satisfactory for operation under certain conditions, none of them can satisfactorily correct for a skewed original. Also, these feeders are, to a greater or lesser extent, relatively costly and difficult to utilize in associated with existing copiers. In addition, certain of these feeders have difficulty feeding originals of intermixed sizes and thicknesses or originals with damaged comers. A relatively complicated sheet feeder and control system is disclosed in US. Pat. No. 2,707,569 in which a vibrator type feeder is actuated from a keyboard by a control linkage to feed checks to a sorting device.

The present invention provides a relatively inexpensive and compact sheet feeder assembly which is suitable for installation on existing copiers or can be provided as original equipment on new copiers. This sheet feeder assembly includes a counter-balanced feed foot which is capable of feeding intermixed sheets of different sizes and weights to a copier or other device even if the sheets are dog-cared, torn or punched. As each sheet is moved forwardly by the feed foot to the copier, the sheet is urged against a side guide or register surface so that a skewed sheet is squared-up without jogging the stack of sheets. The feed foot advantageously includes a friction wheel which is connected with the armature of a vibrator assembly by a one-way clutch which holds the friction wheel against rotation as a sheet is being fed. The one-way clutch enables the friction wheel to idle or roll along a sheet during a return stroke and as the sheet is being forwarded by pick-up rolls in the copier.

Accordingly, it is an object of this invention to provide a new and improved sheet feeder assembly which is relatively inexpensive, compact and capable of feeding intermixed sheets of different weights and sizes.

Another object of this invention is to provide a new and improved sheet feeder assembly which is capable of squaring-up each sheet before it is forwarded into pick-up or receiving rolls.

Another object of this invention is to provide a new and improved sheet feeder assembly in accordance with the next preceding object and wherein the sheet feeder assembly idles" or releases a sheet as soon as it is engaged by the pick-up rolls.

Another object of this invention is to provide a new and improved sheet feeder assembly having a feed foot which is disposed in pressure engagement with a sheet of material and is moved by a vibrator to feed the sheet and wherein a counterbalance arrangement is provided to control the pressure with which the feed foot engages a sheet of material to be fed.

Another object of this invention is to provide a new and improved sheet feeder assembly which includes a feed foot which is disposed in pressure engagement with an uppermost sheet on a pile of sheets and is moved by a vibrator to feed the uppermost sheet, and wherein the feed foot is supported by a linkage arrangement which maintains the feed foot in the same orientation relative to the pile of sheets as the height of the pile is decreased by a feeding of sheets.

Another object of this invention is to provide a new and improved sheet feeder assembly which includes an arcuate friction surface which is moved through 'forward and return strokes by the armature of an electrical vibrator and wherein a one-way clutch connects the friction surface with the armature so as to enable the friction surface to move relative to the sheet during a return stroke and to prevent movement of the friction surface relative to the sheet during a feed stroke.

These and other objects and features of the present invention will become more apparent upon a consideration of the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a schematic pictorial illustration depicting the relationship between a sheet feeder assembly constructed in accordance with the present invention and a known copier;

FIG. 2 is a plan view further illustrating the construction of the sheet feeder assembly of FIG. 1;

FIG. 3 is an elevational view, taken generally along the line 3-3 of FIG. 2, illustrating the relationship between a pile of sheets to be fed to the copier and a feed foot of the sheet feeder assembly;

FIG. 4 is an elevational view, taken generally along the line 4-4 of FIG. 2, illustrating a vibrator assembly for moving the feed foot through forward and return strokes;

FIG. 5 is a schematic illustration of a counter- V balanced four bar linkage which controls the pressure with which the feed foot engages the pile of sheets and maintains a predetennined feed foot orientation relative to the pile as sheets are fed from the pile;

FIG. 6 is an elevational view, taken generally along the line 6-6 of FIG. 2, further illustrating the counterbalanced four bar linkage; and

FIG. 7 is a sectional view, taken generally along the line 5-5 of FIG. 3, schematically illustrating a one-way clutch in the feed foot.

A sheet feeder assembly 10 constructed in accordance with the present invention is illustrated in FIG. 1 in association with a known copier 12. The sheet feeder assembly 10 is operable to quickly feed sheets 16 to be copied from a pile 18 on a support plate or tray 20 to the copier 12. The sheet feeder assembly 10 includes a feed foot 24 which is reciprocated back and forth through feed and return strokes by an electrical vibrator assembly 26. As the feed foot 24 moves forward through a feed stroke, only the uppermost sheet 16 on the stack 18 is moved forwardly into the copier 12.

The feed foot 24 and electrical vibrator assembly 26 are supported on a bracket 30 (FIGS. 2-4) which is connected to a four bar linkage 32 (FIGS. 5 and 6).

The four bar linkage 32 maintains the feed foot 24 in the same orientation relative to the pile 18 as the pile height decreases due to a feeding of sheets from the pile (FIG. 5). A counter-balance arrangement 46 (FIGS. 5 and 6) is connected to the four bar linkage 32 to partially offset the force with which the vibrator 26 and feed foot 24 are urged downwardly under the influence of gravity.

The four bar linkage 32 enables the sheet feeder assembly 10 to feed sheets in the same manner from the pile 18 as the height of the pile is decreased. Thus, the feeding action of the feeder assembly 10 is the same from a relatively high pile level, shown in solid lines in FIG. 5, and a relatively low pile level, shown in dashed lines in FIG. 5. To accomplish this, the four bar linkage 32 maintains the feed foot 24 and vibrator assembly 26 in the same orientation relative to the pile as the height of the pile is decreased.

The four bar linkage arrangement 32 includes a pair of links or bars 33 and 34 which are pivotally connected at 35 and 36 to a fixed housing wall 37 (see FIGS. 5 and 6). The opposite ends of the links 33 and 34 are pivotally connected at 38 and 39 with a link 40 which interconnects the two links 33 and 34. The vibrator assembly 26 and feed foot 24 are connected directly to the link 40. In a specific preferred embodiment of the invention, the link 40 was a continuation of the support bracket 30 for the vibrator assembly 26 and feed foot 24.

As sheets 16 are fed from the pile 18 by operation of the sheet feeder assembly 26, the height of the pile 18 decreases. As the height of the pile decreases, the links 33 and 34 pivot downwardly about their fixed connec tions 35 and 36. During this downward pivotal movement of links 33 and 34, the longitudinal axis of the link 40, indicated at 41 in FIG. 5, moves rearwardly. However, due to the fact that the fourth bar of the linkage 32 is formed by the fixed housing 37, the axis 41 is maintained upright and does not rotate as the links 33 and 34 move downwardly. Therefore, the angular position of the axis 41 and the feed foot 24 relative to the pile 18 remains constant even though the feed foot moves rearwardly somewhat as the height of the pile decreases. Since the angular orientation of the link 40 relative to the pile 18 is maintained constant during feeding sheets from the pile even though the height of the pile is decreased, the feeding action of the feed foot 24 is also maintained constant.

The counter-balance arrangement 46 enables the pressure with which the feed foot 24 engages the uppermost sheet 16 on the stack 18 to be regulated. The counter-balance arrangement 46 includes a counterweight 48 (FIGS. 5 and 6) which is connected with the vibrator 26 and feed foot 24 by the four bar linkage 32. Since the center of gravity of the counterweight 48 is disposed on the downstream side (that is to the left as viewed in FIG. 5) of the axis 35 about which the link 34 rotates, the counterweight 48 tends to pivot the link 33 and feed foot 24 upwardly (that is in a counterclockwise direction as viewed in FIG. 5). Therefore, the counterweight 48 reduces the pressure with which a feed wheel 42 on the feed foot 24 is pressed against the uppermost sheet on the pile 18.

The pressure with which the feed roller or wheel 42 engages the uppermost sheet on the pile 18 is adjustable to facilitate the feeding of sheets having different physical characteristics under different operating conditions. The pressure with which the feed or friction wheel 42 engages a sheet is decreased by moving the counterweight 48 away from the axis 35 about which the link 33 rotates (that is toward the left as viewed in FIGS. 5 and 6). This rearward movement of the counterweight 48 increases its moment arm to increase the counterclockwise moment (as viewed in FIG. 5) applied to the rotatable link 33. Of course, this increased counterclockwise moment on the rotatable support link 33 tends to raise the feed foot and vibration assembly 26 to reduce the pressure with which the feed wheel 42 engages the uppermost sheet 16 on the stack 18.

Similarly, the pressure with which the feed wheel 42 engages the uppermost sheet on the stack 18 is increased by moving the counterweight 48 toward the axis 35 about which the link 33 rotates. This forward movement of the counterweight decreases its moment arm to decrease the counterclockwise moment (as,

viewed in FIG. 5) applied to the link 33. Of course this decreased counterclockwise moment on the rotatable link 33 tends to lower the feed foot 24 to increase the pressure with which the feed wheel 42 engages the uppermost sheet 16 on the stack 18.

To enable the moment arm of the counterweight 48 to be varied, a threaded shaft 50 (FIG. 6) engages nuts 54 and 56 at the link 33. Therefore, the effective length of the shaft 50 and moment arm of the counterweight 48 can be increased by unscrewing the threaded shaft from the nut 56. Similarly, the effective length of the shaft 50 and moment arm of the counterweight 48 can be decreased by screwing the nut 56 further onto the shaft. In this manner, the counterweight arrangement 46 enables the pressure with which the feed roller 42 engages a sheet 16 on the stack 18 to be varied or adjusted to an optimum pressure for the physical characteristics of the particular sheets being fed.

Whenever an original sheet has been processed by the copier 12, the vibrator 26 is activated to feed the next succeeding sheet 16 from the stack 18 to the copier. Thus, the vibrator 26 is electrically connected with copier controls 60 (FIG. 1) by circuitry 62 so that the vibrator 26 is activated to feed a sheet as soon as the preceding sheet has been copied. When the sheet feeder assembly 10 is utilized in association with one specific known type of copier, a coil 64 of the vibrator 26 is electrically energized through a half-wave alternating current rectifier in sequence with a print light for the copier. However, it should be understood that the energization of the coil 64 can be coordinated with the operation of the copier 12 in many different ways depending upon the specific copier with which the sheet feeder assembly 10 is associated.

Upon energization of the vibrator coil 64, the armature 66 is drawn toward a pole piece 68 of the coil against the influence of a leaf spring 70 to move the feed foot 24 rearwardly (that is toward the right as viewed in FIG. 4) through a return stroke. The coil 64 is then deenergized so that the feed foot 24 moves forwardly through a feed stroke, under the influence of the spring 70, to move the uppermost sheet on the stack 18 into the copier 12. As the leading end portion 72 (see FIG. 1) of the uppermost sheet moves into the copier 12, the sheet is moved forwardly by pick-up rolls (not shown) in the copier. Of course, the coil 64 is quickly energized and tie-energized under the influence of a half-wave voltage so that the armature 26 is vibrated in a known manner to move the feed foot 24 through a plurality of feed strokes in a very short time. This results in the uppermost sheet 16 being fed quickly into the copier 12 as soon as the controls 60 detect that the copier is ready for the sheet.

As each of the sheets 16 is moved into the copier, it should be squared-off or side registered so that the material on the sheet can be copied in proper alignment with the edges of a material receiving sheet. To provide for proper registration or squaring-off of each of the sheets 16 in turn, the feed foot 24 is moved slightly inwardly toward a side register plate or surface 76 as it moves forwardly during a feed stroke. This forward and inward movement of the feed foot 24 urges a side edge portion 78 of the sheet being fed into engagement with the side register or guide surface 76. When the side edge portion 78 of the sheet 16 is in engagement with the side register surface 76, the sheet is in proper alignment with the copier 12. Therefore, the sheets 16 in the stack 18 can be fed even though they may be slightly skewed relative to each other.

To provide for this inward and forward movement of the feed foot 24 during a feed stroke, the feed foot is moved forwardly along a path angled slightly inwardly relative to the side register surface 76. Thus, a plane 80 extending perpendicularly to the path of movement of the feed wheel 42 during a feed stroke intersects the side register surface 76 at an acute angle indicated at 82 in FIG. 2. In one specific embodiment of the invention, the angle 82 was 86 so that the feed wheel 42 moves through a feed stroke which was angled inwardly at approximately 4 toward the side register surface 76 to move a skewed or misaligned sheet 16 into engagement with the side register surface.

In addition to being moved along a path which is angled inwardly toward the register surface 76, the feed foot 24 is also angled slightly rearwardly when the vibrator coil 64 is de-energized. This insures that the uppermost sheet 16 on the stack 18 is cleared as the feed foot 24 moves rearwardly through its return stroke. Thus, the angle indicated at 86 in FIG. 4 is an acute angle when the feed wheel or roller 42 is the forwardmost end of its feed stroke. Upon initiation of a return stroke, the feed roller 42 will move slightly upwardly as it is moved rearwardly. Of course, the four bar linkage 32 maintains the angle 86 constant, in the manner previously explained, as the height of the pile 18 is decreased (see FIG. 5). In one specific preferred embodiment of the invention the feed foot 24 is inclined so that the angle 86 has a magnitude of 82. Of course, the particular inclination of the feed foot 24 relative to the side register plate or surface 76 and support plate could differ from the specific angles set forth herein.

During a foreward or feed stroke of the foot 24, the feed wheel 42 is held against rotational movement by a one way clutch 90 which is schematically illustrated in HO. 7. When the feed foot 42 is moved through a rearward or return stroke, the one-way clutch 90 enables the feed wheel 42 to roll along the uppermost sheet 16 on the stack 18 so that it is not moved rearwardly. In addition, the one-way clutch 90 enables the feed wheel 42 to idle or free-wheel as a sheet is moved forwardly under the influence of pick-up rolls (not shown) in the copier 12.

The one-way clutch 90 is of a known construction and includes a cylindrical outer shell or member 94 and an inner clutch member 96. Clutch rollers 102 cooperate with the clutch members 94 and 96 in the manner set forth in US. Pat. No. 3,l84,020. When the feed foot 24 is moved through a forward stroke, the outer clutch member 94 tends to rotate in a generally clockwise direction (as viewed in FIG. 7). However, when the feed foot 24 is moved through a return or rearward stroke, the outer shell 94 of the clutch assembly is moved in a counterclockwise direction (as viewed in FIG. 7) and the outer clutch element 94 is freely rotatable relative to the inner clutch element 96 and support shaft 110. Although many different types of one-way clutches could be utilized, in one specific embodiment of the invention, a Torrington clutch having catalog No. RC-040708 was utilized.

A friction ring or tire 114 is advantageously provided on the outer surface of the cylindrical clutch element 94. The friction ring 114 is formed of an elastomeric material and tightly grips the outer clutch element 94. An annular outer surface 116 of the friction ring 114 grips or frictionally engages the uppermost sheet 16 on the stack 18 to firmly pull the uppermost sheet forwardly during a feed stroke of the foot 24. Of course, the outer clutch element 94 could be provided with many different types of friction surfaces other than the rubber ring or tire 114.

Once the leading end portion 72 of a sheet 16 has been engaged by pick-up rolls (not shown) in the copier 12, the sheet is moved forewardly by the pick-up rolls at a relatively high speed. This high-speed movement of the sheet causes the friction ring 114 and outer clutch element 94 to be rotated at a relatively high speed in the counterclockwise direction (as viewed in FIG. 5) so that the friction ring is free to roll along the sheet as it is pulled forewardly. Of course, if the friction ring 114 was held against rotation as the sheet was pulled forewardly by the pickup rolls in the copier 12, the foreward movement of the sheet would be retarded and the sheet might even be skewed relative to the pick-up rolls.

During a rapid back and forth movement of the feed foot 24, the vibrator assembly 26 and four bar linkage 32 tends to vibrate in a manner which could impair operation of the sheet feeder assembly 10. Accordingly, a vibration dampener arrangement is connected to the vibrator assembly 26. The vibration dampener arrangement 130 includes a weight or mass 132 which is connected with the support bracket 30 for the vibrator assembly 26 by a shaft 134. The weight of the mass 132 tends to impede undesired vertical movement or vibration of the vibrator assembly 26 and feed foot 24 during operation of the sheet feeder assembly 10. Of course, many different types of vibration dampeners could be utilized in place of the specific vibration dampener 130 illustrated herein.

From the foregoing description, it can be seen that the sheet feeder assembly 10 is relatively compact so that it can be readily mounted in association with existing copiers. The sheet feeder assembly 10 includes a feed foot 24 having a friction or feed wheel 42 which engages the uppermost sheet on a pile 18 of sheets with a pressure which is controlled by the counterweight arrangement 46. The four bar linkage 32 maintains a constant angular orientation of the feed foot 24 relative to the pile 18 as sheets are fed from the pile. Since the feed foot 24 engages the uppermost sheet on the stack 18 with the same pressure and at the same angle regardless of the physical characteristics of the sheets and height of the pile 18, the sheet feeder assembly can be utilized to feed intermixed sheets of different weights and sizes. This is because the feed wheel 42 will frictionally engage the uppermost sheet and move it into the copier 12 whether the sheet is relatively thick or thin, with the same feeding action at all pile heights. In addition, the feed wheel 42 is effective to feed sheets which are torn, punched, or dog-cared. As a sheet is moved into the copier 12, it is squared-off or aligned by moving it against the register surface or rail 76.

Having described a specific preferred embodiment of the invention, the following is claimed:

1. A sheet feeder assembly for engaging a sheet of material to be fed from a pile of sheets, comprising;

a feed roller with a one way clutch for enabling said feed roller to rotate about its central axis during a return stroke of said feed roller and for preventing rotation of said feed roller during a feed stroke; vibrator means for moving said feed roller through many rapid feed and return strokes to feed a sheet engaged by said feed roller; mounting means for supporting said vibrator means and feed roller for uniform downward movement thereby maintaining consistant vibration feed impulse in relation to the top sheet as sheets are fed from the top of a pile, and; vibration dampening means for eliminating the effect of said vibrator means in said mounting means and increasing the stroke efficiency of said feed roller.

2. A sheet feeder assembly as set forth in claim 1 wherein said mounting means supports said feed roller for uniform downward movement in such a way as to maintain said feed roller in the same orientation relative to the pile of sheets as said feed roller moves downwardly.

3. A sheet feeder assembly as set forth in claim 1 further including side register surface means extending parallel to a desired direction of sheet feed for engaging one edge portion of the sheet to be fed to position the sheet, said mounting means including means for supporting said feed roller for movement along a path extending at an acute angle to said side register surface means during a feed stroke to enable said feed roller to urge the one edge portion of the sheet against said side register surface means.

4. A sheet feeder assembly as set forth in claim 1 wherein said vibration dampening means consists of a weight attached to said mounting means for causing said mounting means and said vibrator means to remain relatively unaffected by the activation and deactivation of said vibrating means thus causingthe rapid vibrating of said feed roller to engage and feed a sheet of material.

5 UNITED STATES PATENT OFFICE CERTIFICATE CQRRECTION Patent No. 3,144,789 Dated July 10, 1973 Inventoflsi) James A. Kolibas It is certified that error appears in the above-identified patent Z and that said Letters Patent are hereby corrected as shown below:

Column 1, Line 26, "associated" should read "associationW Column 2, Line 52, "5-5" should read "7-7".

Column 7, Line 27,. "in" should read "011" Signed j'a'nd sealed this 8th day of October 1974.,

(SEAL) Attest:

C. MARSHALL DANN Attesting Officer USCOMM-DC 8037 G-PSQ FORM PC9-1050 (10-69) w u.s GOVERNMENT PRINTING omca: 1959 0-366-334 

1. A sheet feeder assembly for engaging a sheet of material to be fed from a pile of sheets, comprising; a feed roller with a one way clutch for enabling said feed roller to rotate about its central axis during a return stroke of said feed roller and for preventing rotation of said feed roller during a feed stroke; vibrator means for moving said feed roller through many rapid feed and return strokes to feed a sheet engaged by said feed roller; mounting means for supporting said vibrator means and feed roller for uniform downward movement thereby maintaining consistant vibration feed impulsE in relation to the top sheet as sheets are fed from the top of a pile, and; vibration dampening means for eliminating the effect of said vibrator means on said mounting means and increasing the stroke efficiency of said feed roller.
 2. A sheet feeder assembly as set forth in claim 1 wherein said mounting means supports said feed roller for uniform downward movement in such a way as to maintain said feed roller in the same orientation relative to the pile of sheets as said feed roller moves downwardly.
 3. A sheet feeder assembly as set forth in claim 1 further including side register surface means extending parallel to a desired direction of sheet feed for engaging one edge portion of the sheet to be fed to position the sheet, said mounting means including means for supporting said feed roller for movement along a path extending at an acute angle to said side register surface means during a feed stroke to enable said feed roller to urge the one edge portion of the sheet against said side register surface means.
 4. A sheet feeder assembly as set forth in claim 1 wherein said vibration dampening means consists of a weight attached to said mounting means for causing said mounting means and said vibrator means to remain relatively unaffected by the activation and deactivation of said vibrating means thus causing the rapid vibrating of said feed roller to engage and feed a sheet of material. 